Communicating Over WiFi Interfaces

The IEEE 802.11 specifications define wireless communications
for local area networks. These specifications and the networks they describe
are referred to collectively as WiFi, a term that is
trademarked by the Wi-Fi Alliance trade group. WiFi networks are reasonably
easy to configure by both providers and prospective clients. Therefore, they
are increasingly popular and in common use throughout the world. WiFi networks
use the same radio wave technology as cellular phones, televisions, and radios.

The Solaris OS contains features that enable you to configure a system
as a WiFi client. This section explains how to use the WiFi connectivity options
of the dladm command to connect a laptop or home computer
to a local WiFi network.

Note –

The Solaris OS does not contain features for configuring WiFi
servers or access points.

Finding a WiFi Network

WiFi networks typically come in three varieties:

Commercially available WiFi networks

Municipal WiFi networks

Private WiFi networks

A
location that is served by WiFi is referred to as a hot spot.
Each hot spot includes an access point. The access point is
a router with a “wired” connection to the Internet, for example,
Ethernet or DSL. The Internet connection is usually through a wireless Internet
service provider (WISP) or traditional ISP.

Commercial WiFi Networks

Many hotels and cafes offer wireless Internet connections as a service
to their customers with laptop computers. These commercial hot spots have
access points within their facilities. The access points are routers with
wired connections to a WISP that serves commercial locations. Typical WISPs
include independent providers and cellular phone companies.

You can use a laptop that runs the Solaris OS to connect to a WiFi network
that is offered by a hotel or other commercial hot spot. Ask for instructions
at the hot spot for connecting to the WiFi network. Typically, the connection
process involves supplying a key to a browser that you launch upon login.
You might have to pay a fee to the hotel or WISP in order to use the network.

Commercial locations that are Internet hot spots
usually advertise this capability to their patrons. You can also find lists
of wireless hot spots from various web sites, for example, Wi-FiHotSpotList.com.

Municipal WiFi Networks

Cities throughout the world have constructed free municipal WiFi networks,
which their citizens can access from systems in their homes. Municipal WiFi
uses radio transmitters on telephone poles or other outdoor locations to form
a “mesh” over the area that the network serves. These transmitters
are the access points to the municipal WiFi network. If your area is served
by a municipal WiFi network, your home might be included in the network's
mesh.

Access to municipal WiFi is usually free. You can access the municipal
network from a properly equipped laptop or personal computer that runs the
Solaris OS. You do not need a home router to access the municipal network
from your system. However, configuring a home router is recommended for areas
where the signal from the municipal network is weak. Home routers are also
recommended if you require secure connections over the WiFi network. For more
information, see Secure WiFi Communications.

Private WiFi Networks

Because WiFi networks are relatively easy to configure, companies and
universities use private WiFi networks with access limited to employees or
students. Private WiFi networks typically require you to supply a key when
you connect or run a secure VPN after you connect. You need a properly equipped
laptop or PC that runs the Solaris OS and permission to use the security features
in order to connect to the private network.

Planning for WiFi Communications

Before you can connect your system to a WiFi network, complete the following
instructions.

How to Prepare a System for WiFi Communications

Before You Begin

The following preparations assumes that your system
is a laptop or personal computer that runs the Solaris Express, Developer Edition 2/07 or later release.

Equip your system with a supported WiFi interface.

Your
system must have a WiFi card that is supported by Solaris. For the Solaris Express, Developer Edition 2/07 and later releases, you can
use WiFi cards that support most Atheros chip sets. For a list of currently
supported drivers and chip sets, refer to Wireless
Networking for OpenSolaris.

If the interface is not already present on the system, follow the manufacturer's
instructions for installing the interface card. You configure the interface
software during the procedure How to Connect to a WiFi Network.

Locate your system in a place that is served by a WiFi network,
either commercial, municipal, or private.

Your system must be
near the access point for the network, which is normally not a consideration
for a commercial or private network hot spot. However, if you plan to use
a free municipal network, your location must be near the transmitter access
point.

(Optional) Set up a wireless router to serve as an additional
access point.

Set up your own router if no WiFi network is available at your
location. For example, if you have a DSL line, connect the wireless router
to the DSL router. Then the wireless router becomes the access point for your
wireless devices.

Connecting and Using WiFi on Solaris OS Systems

This section contains tasks for establishing and monitoring WiFi connections
for a laptop or desktop computer that runs the Solaris OS.

In this example, the output indicates that two links are available.
The ath0 link supports WiFi communications beginning with
the Solaris Express, Developer Edition 2/07release. The e1000g link is for attaching
the system to a wired network.

In this example, the output indicates that the system is now connected
to the net3 network. The earlier scan-wifi output
indicated that net3 had the strongest signal among the
available networks. The dladm show-wifi command automatically
chooses the WiFi network with strongest signal, unless you directly specify
a different network.

Access the Internet through the WiFi network.

Do either
of the following, depending on the network to which the system is connected:

If the access point offers free service, you can now run a
browser or an application of your choice.

If the access point is in a commercial hot spot that requires
a fee, follow the instructions provided at the current location. Typically,
you run a browser, supply a key, and give credit card information to the network
provider.

Conclude the session.

Do one of the
following:

Terminate the WiFi session but leave the system running.

# dladm disconnect-wifi

Terminate a particular WiFi session when more than one session
is currently running.

# dladm disconnect-wifilink

where link represents the interface that
was used for the session.

Cleanly shut down the system while the WiFi session is running.

# shutdown -g0 -i5

You do not need to explicitly disconnect the WiFi session prior to turning
off the system through the shutdown command.

Example 3–1 Connecting to a Specific WiFi Network

The following example shows a typical scenario that you might
encounter when using a laptop that runs the Solaris Express, Developer Edition 2/07 or later Developer
releases in an Internet coffee house.

Learn whether a WiFi link is available.

# dladm show-wifi
ath0 type: non-vlan mtu: 1500 device: ath0

The ath0 link is installed on the laptop. Configure
the ath0 interface, and verify that it is up.

The output indicates that net3 has the best signal. net3 requires a key, for which the provider for the coffee house
charges a fee. citinet is a free network provided by the
local town.

Connect to the citinet network.

# dladm connect-wifi -e citinet

The -e option of connect-wifi takes
the ESSID of the preferred WiFi network as its argument.
The argument in this command is citinet, the ESSID of
the free local network. The dladm connect-wifi command
offers several options for connecting to the WiFi network. For more information,
refer to the dladm(1M) man
page.

The Solaris OS automatically chooses the optimal speed for
the WiFi connection. Modifying the initial speed of the link might cause reduced
performance or prevent the establishment of certain WiFi connections.

You can modify the link speed to one of the possible values for speed
that is listed in the show-linkprop output.

Secure WiFi Communications

Radio wave technology makes WiFi networks readily available and
often freely accessible to users in many locations. As a result, connecting
to a WiFi network can be an insecure undertaking. However, certain types of
WiFi connections are more secure:

Connecting to a private, restricted-access WiFi network

Private networks, such as internal networks established by corporations
or universities, restrict access to their networks to users who can provide
the correct security challenge. Potential users must supply a key during the
connection sequence or log in to the network through a secure VPN.

Encrypting your connection to the WiFi network

You
can encrypt communications between your system and a WiFi network by using
a secure key. Your access point to the WiFi network must be a router in your
home or office with a secure key-generating feature. Your system and the router
establish and then share the key before creating the secure connection.

The dladm command can use a Wired Equivalent Privacy
(WEP) key for encrypting connections through the access point. The WEP protocol
is defined in IEEE 802.11 specifications for wireless connections. For complete
details on the WEP-related options of the dladm command,
refer to the dladm(1M) man
page.

How to Set Up an Encrypted WiFi Network Connection

The next procedure shows how to set up secure communications
between a system and a router in the home. Many wireless and wired routers
for the home have an encryption feature that can generate a secure key. This
procedure assumes that you use such a router and have its documentation available.
The procedure also assumes that your system is already plugged into the router.

Start the software for configuring the home router.

Refer
to the manufacturer's documentation for instructions. Router manufacturers
typically offer an internal web site or a graphical user interface for router
configuration.

Generate the value for the WEP key.

Follow the manufacturer's
instructions for creating a secure key for the router. The router configuration
GUI might ask you to supply a passphrase of your choice for the key. The software
then uses the passphrase to generate a hexadecimal string, typically 5 bytes
or 13 bytes in length. This string becomes the value to be used for the WEP
key.